The effects of ultrasound on the activities of alpha-amylase and amyloglucosidase toward starch and glycogen hydrolysis, and of invertase toward sucrose hydrolysis, were investigated using an ultrasound bath. A fixed-time assay was employed with product formation determined by reducing equivalents formed per unit time using the 3,5-dinitrosalicylate reagent (DNS). Reaction rates in the presence and absence of ultrasound were compared. Increases in rates were observed in the presence of ultrasound at most concentrations with a marked increase in invertase activity towards sucrose (37% at 0.9 M) and a reduction in the inhibition of sucrose hydrolysis observed at high substrate concentrations. Improvements in the efficiency of mixing and disruption of intra- and intermolecular substrate molecule interactions at high concentrations are possible explanations for the changes observed.